Pumps



0. E. ROSAEN Oct. 12, 1965 PUMPS 4 Sheets-Sheet 1 Filed Aug. 2, 1963INVENTOR. OSCAR EROSAEN ATTO R NEYS 0. E. ROSAEN Oct. 12, I965 PUMPS 4Sheets-Sheet 2 Filed Aug. 2, 1963 INVENTOR. OSCAR E.ROSAEN v ATTORNEYSOct. 12, 1965 o. E. ROSAEN 3,211,104

PUMPS Filed Aug. 2, 1963 4 Sheets-Sheet 5 as. H61

4 A- I; I

34 33 INVENTOR.

OSCAR E.ROSAEN 33A 3 33 BYv A I Fl 6.9. 30

ATTORNEYS 0. E. ROSAEN Oct. 12, 1965 PUMPS 4 Sheets-Sheet 4 Filed Aug.2, 1963 w e H iGB INVENTOR. O$AR E. ROSAEN ATTORNEYS United StatesPatent f 3,211,104 PUMPS Oscar E. Rosaen, Grosse Pointe, Mich. FiledAug. 2, 1963, Ser. No. 303,198 Claims. (Cl. 103-136) The presentapplication is a continuation-in-part of my copending application Ser.No. 90,294, filed Feb. 20, 1961, now abandoned.

The present invention relates to rotary vane type fluid pumps and moreparticularly to an improvement in pressure balancing of the vanes ofsuch pumps as those I have disclosed in my copending application Ser.No. 765,605, filed Oct. 6, 1958 now Patent No. 3,000,324 issued Sept.19, 1961 and Ser. No. 765,606, also filed Oct. 6, 1958.

US. Patents Nos. 2,612,114 and 2,612,115 issued to W. Ernst on Sept. 30,1952 disclose and claim vane type pumps in which pressure balancing ofthe vanes is achieved by providing an axial bore beneath each vaneelement and by providing means for regulating the pressure in the axialbores to maintain contact between the ends of the vane element and thecam surface. It has been found that in pumps of the type disclosed inthe aforementioned Ernst patents that as the vanes travel through thearea between the outlet and the inlet of the pump the inlet suctionpressure on the forward face of the vane element and the high outletpressure on the rearward face of the element causes the element to moveagainst the forward face of the vane slot. The fluid on the rearwardside of the vane element then escapes beneath the vane element andbecause a sealing fit cannot be produced between the vane slot and theforward face of the vane element, fluid beneath the vane element willescape to the suction side of the vane element.

To overcome this problem many other types of pumps have been provided inwhich slipper elements or the like are provided to replace the vaneelements. Such pumps are disclosed in US. Patents Nos. 3,009,420 and3,009,421, issued to W. T. Livermore et al. on Nov. 21, 1961. Such pumputilize a portion of the pressure beneath the slipper elements to forcethe depending legs of the elements against the sides of the slots. Inthis way a seal is produced and the fluid beneath the element isprevented from escaping. Such pumps have the disadvantages that theslipper elements are difficult and expensive to manufacture and highpressures must be maintained beneath the element to insure the necessarycontact between the end portions of the element and the cam ring becauseof the resistance to outward movement of the element produced by thesealing contact between the legs of the element and the sides of theslot.

In the pumps disclosed in my first mentioned copending applications theeffectiveness of pressure balancing of the vanes is insured by usingvane-like sealing elements positioned intermediate the pumping vanes.The sealing vanes contact the cam ring during travel through thecritical area from the outlet or discharge port to the inlet area of thechamber and thus seal the rearward face of the pumping vanes from thehigh outlet pressure. Although the sealing vanes effectively eliminatethe problem in this area of the pumping cycle, they are rather small andhence diflicult to manufacture and handle and constitute an addedexpense in the manufacture of vane type pumps.

The present invention eliminates the need for such sealing vanes byproviding a means of utilizing the differential in pressures in the areabetween the inlet and the outlet to tip the vane element and produce asealing engagement between portions of the vane element and the walls ofthe slot. In this way pressure beneath the vane is sealed in andprevented from escaping.

3,211,104 Pateiited Oct. 12, 1965 One object then of the presentinvention is to maintain pressure balancing of the vane elements in allareas of the pumping cycle without the necessity of using sealing means.

Another object of the invention is to improve rotary vane pumps byproviding vane elements which are ballanced by fluid pressures as nearlyas possible in all directions to provide silent operation andelimination of pressure surges.

A further object of the invention is to simplify manufacture, handlingand assembly of rotary vane pumps by providing passages for fluidpressure operative to maintain pressure balancing on the vanes at alltimes.

Yet another object of the invention is to improve rotary vane pumpoperation by providing pressure balanced vanes which in themselves act,during travel from the outlet areas to the inlet areas of the pumpingchamber, to provide a sealing engagement with the sides of the slot tomaintain a separation of the fluid pressures acting on the vane elementsduring such periods of travel.

For a more complete understanding of the present invention, referencemay be had to the accompanying drawings in which like referencecharacters refer to like parts throughout the several views and in whichFIG. 1 is a longitudinal cross-sectional view of a preferred rotary vanepump embodying the invention and as taken substantially on the line 11of FIG. 2.

FIG. 2 is a cross sectional view of the pump taken substantially on theline 22 of FIG. 1.

FIG. 3 is a cross-sectional view of the pump taken substantially on theline 2-2 of FIG. 1.

FIG. 4 is a cross-sectional view of a cheek plate portion of the pump ona plane normal to the plane of the cross-section of FIG. 1.

FIG. 5 is an axial elevational view of the rotor and cam components ofthe pump.

FIG. 6 is a side elevational View of the cam component shown in FIG. 5.

FIG. 7 is an elevational plan view of'a vane embodied in the pump rotor.

FIG. 8 is an end elevational view of said vane.

FIG. 9 is a cross-sectional view taken substantially on line 9-9 of FIG.7.

FIG. 10 is an enlarged fragmentary elevational view of structure shownin FIG. 5, and

FIG. 11 is a view similar to FIG. 10 but illustrating another preferredconstruction of the pump of the present invention.

Description The preferred pump 10 comprises a housing structure 11provided with an end plate 12 enclosing a substantially cylindricalpumping chamber 13. An inner cheek plate 14 and an outer cheek plate 15are disposed in the chamber 13 with an annular cam ring 16 disposedbetween them and having a cam surface 16A forming the peripheral surfaceof a rotor chamber 16B. A rotor 17 is rotatably carried in the chamber16B and is keyed to a drive shaft 18 supported by a bearing 18A at oneend of the housing 11 and a bushing 18B mounted in the outer cheek plate15.

The housing 11 has a fluid inlet 19 connected with similar anddiametrically opposite inlet grooves 20 in the sides of the chamber 13to form passages extending axially between the wall of the chamber 13and the outer surfaces of the cam ring 16.

The grooves 20 admit fluid to intake openings 21 in the cam ring 16,fluid thence entering the rotor chamber 16B at what is for purposes ofdiscussion herein called the inlet areas of the chamber 16B. Theopenings 21 are elongated as at grooves 21A shown in FIGS. 2 and 5 toprovide inlet areas greater in annular length than the space between twoadjacent rotor vanes.

Fluid will be impelled annularly around the spaces of the rotor chamber16B between the cam surfaces 16A and the rotor 17 to an outlet area inthe location of cam surface slopes 22. A pair of diametrically oppositeaxially extending discharge openings 23 are provided in the cam ring 16and are connected by grooves 23A with the outlet areas of the rotorchamber 16B. The grooves 23A, like the grooves 21A, are greater inannular length than the space between adjacent rotor vanes. Fluid fromthe discharge openings 23 is forced under pressure out through passages24 provided in the inner cheek plate 14, through discharge passages 25and 26 in the housing 11 to a pressure fluid outlet 27.

The ressure flow is produced by means of a plurality of axiallyelongated rotor vanes 30 radially slidably carried in a plurality ofequally annularly spaced slots 31 provided around the periphery of therotor 17.

Each slot 31 communicates at its inner end with axially bored holes 32as shown. In operation, as the rotor 17 turns, the outer edges of thevanes 30 are quided along the cam surfaces 16A, the vanes 30 retractingin the slots 31 as they follow the cam slopes 22. Fluid is thus impelledfrom the inlet to the outlet areas.

Each vane 30, as shown in FIGS. 7, 8 and 9, is provided on its forwardface with a radialy extending groove 33 and the forward outer edge isbeveled as at 34 to provide substantially line contact between the vanes30 and the cam surface 16A, the vanes thereby being readily held outwardby the pressure under the vanes as will be described, the outer end 33Aof the groove 33 being spaced slightly from the bevel 34.

As shown in FIGS. 2 and 5, the forward outer edges of the slots 31 arebeveled as at 31A. When the vanes 30 are extended during travel from theinlet to the outlet areas of the chamber 163, the outer ends 33A of thegrooves 33 are radially outward of the slot bevel 31A, the fluid presureis transmitted to the inner ends of the slots at the holes 32, so thatboth ends of the vanes 30 are subjected to substantially equalpressures. Moreover, as the vanes move from the inlet to the outletareas, pressure on the forward face is substantially balanced againstthe pressure on the rearward face, in the same fashion as that describedin my prior patents. Thus, as pressure rises in the chamber 16B ahead ofeach vane, the pressure also rises equally underneath the vanes 32,providing for extremely silent operation with practically no pressuresurges.

A difference occurs, however, as each vane 30 is re- I tracted by thecam slope 22. Then the groove 33 is closed off by the slot 31, so that,as the vanes move from the outlet area to the inlet area, communicationbetween the holes 32 and suction side of the vane 30 is substantiallyclosed. Without more, however, the high pressure on the outlet side ofthe vane element 30 and the suction pressure on the inlet side of thevane element 30 would coact to press the vane element 30 against theforward face of the slot 31. Outlet pressure would then enter the hole32 and escape between the leading face of the vane element 30 and thewall of the slot 31 to the suction side of the element 30. To preventthis, the slots 31 are beveled as at 31A. As can best be seen in FIG.the slot bevel 31A provides a fulcrum at 37B which permits the vanes 30to tip. As the vane element 30 enters the area between the outlet andthe inlet a pressure differential is produced across the extended end ofthe vane element 30. The pressures between the faces of the vane elementand the sides of the slot 31 as well as the pressure beneath the vaneelement 30 will vary but will be somewhat intermediate the suctionpressure on the forward face of the extended portion of the vane element30 and the high outlet pressure on the rearward face of the extendedportion of the vane element 30. For this reason the vane element 30 willbe caused to tip forward as illustrated in FIG. 10 and cause asubstantially tight line contact between the rearward faces of the vanesand the inner edge of the slots 31 at the point 37 shown in FIGS. 5 and10, and also between the forward faces of the vanes 30 and the outeredge of the slots 31 at the point 37B, preventing leakage of pressurepast the vanes 30.

It is apparent that without the slot bevel 31A not enough of the surfaceof the vane elements 30 would be exposed to the suction pressure andoutlet presure to produce the tipping required to effectively seal theholes 32. The slot bevel 31A performs the dual function of promotingtipping of the vane element 30 by exposing a greater portion of the vaneelement to the pressure differential which produces the tipping and byproviding the fulcrum point 37B upon which the vane element 30 can tipas well as providing the closing point of the groove 33 below thehalfway point of balance between the inner and outer ends of the slot31. In the embodiment illus trated in FIGS. 1-10 the beveled face 34 ofthe vane elements 30 provide substantially line contact between thevanes 30 and the cam surface 16A.

In order to equalize the pressure on the outer ends of the vanes 30 withthe pressure sealed behind the vanes 30 as the grooves are closed off onretraction and the vanes tip as described above, a port 35 is providedin the inner cheek plate 14 in a position to register momentarily withthe holes 32 at the inner ends of the slots 31 as they successively passfrom the outlet areas. The ports 35 are openly connected with the outletpassages 24 by means of passages 36.

As the vanes 30 reach the inlet areas, and begin to extend the holes 32move into registry, with elongated slots 38 provided in both inner andouter cheek plates 14 and 15. These slots communicate with the housinginlet grooves 20 via radially extending passages 39. This admitssubstantially atmospheric pressure to the inner ends of the vanes 30,the outer ends thereof being subjected to the less than atmosphericpressure at the inlet areas of the chamber 16B, causing the vanes 30 toextend.

FIG. 11 is a view similar to FIG. 10 but illustrates a preferredmodification of the present invention. In FIG. 10, it will be noted thebeveled face 34 of the vane element 30 is angled such that when the vaneelement 30 is in the retracted position, the edge of the bevel 34 andthe leading face of the vane element is disposed above the line 37B. Inthis way the edge of the slot bevel 31A acts as the fulcrum upon whichthe vane element 30 is tipped. By extending the length of the bevel 134of the vane element as shown in FIG. 11, the fulcrum upon which the vaneelement 130 will tip becomes the edge 137B formed by the bevel 134 andthe leading face of the vane element 130.

The vane 130 is provided with a recessed portion 137C on the lowerportion of the rearward face as shown in FIG. 11 so that a fulcrum point137 is also provided on the rearward face of the vane 130.

It is possible in either of the modifications described above toregulate the pressure permitted in the hole 32 before the vane elements30 or 130 tips by changing the position of the fulcrum 37B, 137B, 137.In this way, the force with which the vane 30 or 130 engages the camsurface 16A can be regulated. The embodiment illustrated in FIG. 11 hasthe added advantage that this can be readily accomplished. All that isnecessary is to replace the vane elements 130 with new vanes having thedesired fulcrum point.

For example, if the dimensions shown in FIG. 11 are used, and the pumpis operating at 1000 p.s.i., then the moment at point 137B will equalthe moment at point 137 less the unbalancing force on the forward sideof the vane between the fulcrum points 137B and 137, or:

6-1000-3 equals 8-l0OO-4(84 P) P equals 437 Where P is the pressure inp.s.i. under the vane. The

force under the vane, which is one inch wide, urging it against the camring will thus be 51 lbs. since 3 mm. equals 0.117 in. and

0.117 437 1" equals 51 Therefore, it is clear that choosing thepositions of the fulcrums actualy makes-the vane itself regulate theeffective pressure under the vane to whatever value is desired.

It is also apparent that although I have described but two modificationsof my invention, many changes can be made without departing from thespirit of the invention as expressed by the scope of the appendedclaims.

I claim:

1. A rotary vane pump comprising (a) a housing provided with a chamberhaving a peripheral wall,

(b) annularly spaced inlet and outlet ports connected respectively withsuction and pressure portions of said chamber,

() a rotor rotatable in said chamber and having annularly spacedradially extending slots,

(d) vanes radially slidable in said slots and having outer ends guidedin radial extension and retraction by said peripheral wall duringrotation of said rotor,

(e) means providing a fulcrum line between the forward facing portion ofsaid vanes and the adjacent face of said slot and a sealing line betweenthe rearward facing portion of said vanes and the adjacent face of saidslot, said fulcrum and sealing lines being at all times at fixedrelative positions, whereby when pressure on the rearwardly facing sideof said vane is greater than the pressure on the forwardly facing sidethereof, said vane will be caused to tip on said fulcrum to producesealing line contact at the fulcrum line and the sealing line with thefaces of said slot.

2. A rotary vane pump comprising,

(a) a housing provided with a chamber having a peripheral wall,

(b) annularly spaced inlet and outlet ports connected respectively withsuction and pressure portions of said chamber,

(c) a rotor rotatable in said chamber and having spaced radial slots,

((1) vanes radially slidable in said slots and having outer ends guidedin radial extension and retraction by said peripheral wall duringrotation of said rotor,

(e) means causing each vane to tilt in its slot to make line sealingcontact therewith when pressure on the rearwardly facing side of thevane is greater than the pressure on the forwardly facing side thereof,

(f) said means comprising said slot having a radially outward rearwardlyfacing face portion beveled at an angle with respect to the radiallyinward portion to provide a fulcrum adjacent the forwardly facing sideof said vane on which said vane is caused to tilt, and

(g) said slot having a shoulder providing an edge adjacent the oppositeside of said vane with said line sealing contact being obtained at saidedge. 3. The pump as defined in claim 2 and in WhlCh the inner end ofthe beveled portion of said slot is located about midway between theinner and outer ends of the slot.

4. A rotary pump comprising,

(a) a housing provided with a chamber having a peripheral Wall,

(b) annularly spaced inlet and outlet ports connected respectively withsuction and pressure portions of said chamber,

(c) a rotor rotatable in said chamber and having spaced radial slots,

(d) vanes radially slidable in said slots and having outer ends guidedin radial extensions and retraction by said peripheral wall duringrotation of said rotor,

(e) means causing each vane to tilt in its slot to make line sealingcontact therewith when pressure on the trearwardly facing side of thevane is greater than the pressure on the forwardly facing side thereof,

(f) said means comprising said vane having a radially outward faceportion beveled at an angle with respect to the radially inward portionto provide a fulcrum adjacent the rearwardly facing face of said slot onwhich said vane is caused to tilt, and

(g) said vane having a shoulder providing an edge adjacent the oppositeface of said slot with said line sealing contact being obtained at saidedge.

5. A rotary vane pump comprising,

(a) a housing provided with a chamber having a peripheral wall,

(b) annularly spaced inlet and outlet ports connected respectively withsuction and pressure portions of said chamber,

(c) a rotor rotatable in said chamber and having spaced radial slots,

(d) vanes radially slidable in said slots and having outer ends guidedin radial extension and retraction by said peripheral wall duringrotation of said rotor,

(e) means causing each vane to tilt in its slot to make line sealingcontact therewith when pressure on the rearwardly facing side of thevane is greater than the pressure on the forwardly facing side thereof,

(f) the inner end of said slots each having an enlarged portion definingan edge on the inner end of the forwardly facing face making linecontact with the rearward face of the vane when it tilts, and

(g) said slot having a fulcrum on the opposite face making line contactwith the forward face of the vane.

References Cited by the Examiner UNITED STATES PATENTS 2,371,081 3/45Tucker et al. 103--136 2,435,279 2/48 I-Iubacker 103-136 3,008,424 11/61Roth 103-136 3,076,415 2/63 Farron 103136 3,159,336 12/64 Paschke 230FOREIGN PATENTS 30,312 10/59 Finland.

DONLEY J. STOCKING, Primary Examiner.

JOSEPH H. BRANSON, 111., Examiner.

1. A ROTARY VANE PUMP COMPRISING (A) A HOUSING PROVIDED WITH A CHAMBERHAVING A PERIPHERAL WALL, (B) ANNULARLY SPACED INLET AND OUTLET PORTSCONNECTED RESPECTIVELY WITH SUCTION AND PRESSURE PORTIONS OF SAIDCHAMBER, (C) A ROTOR ROTATABLE IN SAID CHAMBER AND HAVING ANNULARLYSPACED RADIALLY EXTENDING SLOTS, (D) VANES RADIALLY SLIDABLE IN SAIDSLOTS AND HAVING OUTER ENDS GUIDED IN RADIAL EXTENSION OF SAID ROTOR, BYSAID PERIPHERAL WALL DURING ROTATION OF SAID ROTOR, (E) MEANS PROVIDINGA FULCRUM LINE BETWEEN THE FORWARD FACING PORTION OF SAID VANES AND THEADJACENT